1. Field of the Invention
The present invention relates to a wireless communication technology using a wireless local area network (LAN).
2. Description of the Related Art
A network configuration of a wireless LAN conforming to IEEE802.11 standard includes an infrastructure mode and a wireless distribution system (WDS) mode. A network in the infrastructure mode is configured between a base station for configuring a wireless LAN and a terminal station connected to the wireless LAN. A network in the WDS mode is configured between base stations.
Japanese Patent Application Publication No. 2007-28124 describes a wireless communication system including a connection device as a first base station for configuring a first wireless LAN and a relay device as a second base station for configuring a second wireless LAN. The relay device functions as a terminal station in the infrastructure mode for the first wireless LAN and functions as a base station in the infrastructure mode for the second wireless LAN. Accordingly, the relay device relays a data frame to be communicated between a terminal as a terminal station connected to the second wireless LAN and the connection device as the first base station. The relay device prepares a table associating an IP address of a network layer address and a Media Access Control (MAC) address of a link layer address with each other and a destination MAC address of a data frame is converted using the table, so that the relay device can relay data transferred through the connection device to each of the terminals.
Since the above-described wireless communication system executes address conversion in the relay device using the table associating an IP address of a network layer address and a MAC address of a link layer address with each other, data that can be relayed in the wireless communication system is limited to data conforming to a specific communication protocol set in the relay device. For example, in a case in which the relay device supports only IPv4, if a node in a wide area network or a communication device such as a connection device or a wireless LAN terminal supports not only IPv4, but also IPv6, an IPv6 packet cannot be converted in the relay device. Therefore, if communication according to IPv6 is conducted through the relay device, a communication failure occurs. It may be preferable that the wireless communication system should be able to relay not only data conforming to IPv4, for example, but also data conforming to any other communication protocol of IPv6, IPX, SPX and the like.